1. Field of the Invention
The following invention relates to keyboards, and more particularly to a keyboard formed in two or more mutually pivotable segments which may be adjusted and locked into a number of different ergonomic positions.
2. Description of the Prior Art
Known keyboards of the type used at a computer terminal, for example, generally include a unitary board onto which alphanumeric keys are attached. It is a disadvantage of such known keyboards that the wrists and/or arms and shoulders of an operator must be contorted into a configuration which is stressful to the user after prolonged use of the keyboard. This problem is brought about by the fact that the hands of the user must be turned outwardly by pivoting of the wrists relative to the forearms, resulting in ulnar deviation. Discomfort to the user caused by pronation of the wrists is also a problem with these known keyboards. Pronated posture can also transmit stresses into the neck and shoulders of the user.
It is desirable to reduce pronation and ulnar deviation of the wrists in computer keyboards. To that end, U.S. Pat. Nos. 5,424,728 and 5,543,790 describe adjustable keyboards with at least two segments which are movable relative to one another via a hinge or joint. By moving the segments, the orientation of the user""s wrists and hands can be adjusted to allow for reduction of ulnar deviation and pronation of the wrists. The hinge or joint in those patents is disclosed as preferably being a ball and socket-type joint.
U.S. Pat. Nos. Des. 362,434 and 5,454,52, assigned to Lexmark and U.S. Pat. No. 5,527,116, assigned to Maxi Switch, each show adjustable keyboards including a mechanism for locking the keyboard segments in place. However, in each of the keyboards described in those patents, the locking mechanism includes a large number of parts. As a result, those keyboards can be difficult to manufacture and assemble and therefore can be expensive, and those keyboards can be difficult for the user to adjust and lock.
It is the object of the present invention to overcome or substantially ameliorate the disadvantages of the prior art. It is therefore an object of the present invention to provide an adjustable keyboard which is inexpensive and simple to manufacture, is made of few parts and parts which are easy to manufacture and assemble, and which is easy for the user to adjust to a large number of positions.
There is disclosed a keyboard having a plurality of keys, the keyboard having at least two segments which are mutually movable relative to one another, and wherein each segment of the keyboard includes some of the keys. Typically, the keyboard has at least two mutually pivotable segments which are attached to one another at a top end of the keyboard segments by way of a hinge or joint, such that a front edge of the keyboard may spread apart in at least a substantially horizontal plane, to thereby reduce ulnar deviation in the keyboard user. Advantageously, the hinge or joint is adapted to allow pivoting in both horizontal and vertical planes such that the two segments of the keyboard may reside in different planes, so that the center of the keyboard is raised to reduce pronation and therefore decrease tension in the wrists and forearms of the user.
The hinge or joint may preferably be composed of a ball and socket joint which includes a locking mechanism. The locking mechanism may be fashioned using a pivoting handle, in the form of a lever, which includes a cam. The cam may be used to force bearing surfaces against a ball on a ball element, to thereby frictionally retain the ball and socket joint in a fixed position. Upon pivoting of the handle away from the keyboard, the cam may release the ball from the friction fit with the bearing surfaces, thereby allowing the ball to slide in the socket, and therefore allowing the keyboard segments to be adjusted relative to one another.
A support may be provided generally below the ball and socket joint so as to maintain the central region of the keyboard at a raised preselected level, if needed.
Beneficially, a number pad region of the keyboard can be provided which is pivotable relative to one of the segments such that the number pad region may reside in a plane other than the plane of the segment to which the number pad is hinged.
Typically, the keyboard is divided into segments which coincide with generally accepted keyboard areas used by a particular hand.
The present invention provides a keyboard in which the wrists of the operator need not be contorted as they would be in use of a conventional keyboard.
In order to electrically connect the keys of one segment of the keyboard to the other, a cable or any suitable contact may be provided between the two segments. Additionally, an infrared or other electromagnetic signal may be used to transmit signals from the keyboard to the computing device without the need for a cable or other physical connection.